Brake for axminster loom pull-over shafts



D ec- 12, 1944 l N. FLETCHER Erm. 2,364,703

BRAKE FOR IAXMINSTER LOOM PULL-OVER SHAFTS Original Filed Sept. 28, 1942 2 Sheets-Sheet 1` ATroRNcY Dec. 12, 1944. N. Flfs'rcHER ETAL 2,364,703

BRAKE FOR AXIINSTER LOOM PULL-OVER SHAFTS Original Filed'Sept. 28, 1942 2 Sheets-Sheet 2 INvcNTone ATTORNEY Patented Dec. 12, 1944 BRAKE FOR AXMINsrER LOOM runt-OVER sHAF'rs l Norman Fletcher, Worcester, and Walter Y. Robb,

Massi, assi Knowles Loom Works,

ghors to Crompton & Worcester, Mass., la lcor.-

poration of Massachusetts Original application September- 248, 1942, Serialv N0.` v459,936. March 8, 1943,

6 Claims.

'I'his is a division of our co-pending application Serial No. 459,936, liledSeptember 28, 1942, now Patent #2,345,334, Mar. 28, 1944.

f 'I'his invention relates to Axminster looms and Iit is the general objectof the invention to provide brake mechanism for the tube frame pullover shafts of such looms.

Axminster looms operate with a series of tube frames which are moved by a pullover shaft one 'at a time to transfer position from which they are moved by transfer arms toward and from the vcloth for the formation of tufts. It is essential Divided and i Serial No. 478,388

this application that the transporting chains which carry the frames and are driven fixed position to turned to them.

A 'pullover shaft brake of vthe type shown in 'patent to Jenckes No. 1,470,007 is not readily adaptable to wide Axminster looms wherein considerable pressure must be exerted by the brake shoes to hold the pullover shaft stationary. This previously patented mechanism uses a spring wh'ich, in order to be effective on wide looms, must be so strong as to interfere with manual release of the brake. It is an important object of our presen-t invention to apply two brake arms to the pullover shaft and connect them by a readily releasable mechanism, such as an eccentric, which permits automatic operation by a hy- Idraulic cylinder.

It is another object of our present invention to consolidate the pivot for the brake arms with aman'ual releaser in such a Way that the means by which the .brake can be manually relieved is 'also the pivot for the arms. The mechanism thus 'simplified uses fewer parts but permits the application of a greater braking force than is feasible with previouslyv proposed brakes.

It is a still further object of our invention to attach the two brake arms together by a form of connection which includes an eccentric normally serving as a pivot for 'the arms but rotatable manually to releasethe arms when it is desired to move the ,pullover shaft independently of the loom.

It is a still further object of our present invention to provide a pair of brake shoes adapted for cooperation with a hydraulic'brake connected to Aa master cylinder whic relation with the mechanism which turns the `pullover shaft.

With these and other 'objects in view which will appear as the description proceeds, our invvention resides in the combination and arrangement of parts hereinafter described and set forth.

by the shaft be held in register with the tube frame re- In the accompanying drawings, wherein two orms of 'our invention are set forth,

Fig. 1 is a side elevation of a portion of an Axminster loom` having our invention applied v thereto, l

2 is an enlarged transverse vertical section through the pullover shaft 'and showing the preferred form of the mechanism,

Fig. 3 is a front `elevation looking in the direction yof 'arrow 3, Fig. 2, l v

Fig. 4 is a diagrammatic view showing the Operation of the eccentrics -s'et forth in Fig. 2,

Fig. 5 is an enlarged vertical section on line 55 of Fig. 2, y

Fig. 6 is a view similar to Fig. 2 but showing the modified form of combined brake arm pivot and manual release, y

Fig. 7 is a vertical sectioncn line 1 1 of Fig. 6,

Fig. 8 is a diagrammatic view of the two cams which operate the pullover shaft `operating and brake mechanisms, 'and Fig. 9 is a vertical section through the master hydraulic cylinder.

' Referring to the drawings, Fig'. 1 shows a loom frame I0 in the vrupper part of which is mounted a pullover shaft I 'I on which are mounted feeding arms I3 and I4 connected by krods I5 and IE, respectively, to a cam lever I1. The lever is pivoted as at I8 and carries a roll I9 received `by the groove of a cam 20 secured to the loom shaft `-2I. Sprockets 22 on shaft I I and their tube frame transporting chains C., one of each being shown in Fig. 1move with the shaft. In the present instance shaft II makes a rotation every third pick of the loom to produce so-called three-shot Axminster weave, lbut we are not limit-ed in the practice of our invention this time.

A shield` 25 is pivoted to the loom frame 4at 26 and can assume any one of three positions in the central or neutral one of which both levers I3 and I4 are prevented from turning the pullover shaft and in the other positions of which either arm I3 or arm I4 will turn the shaft clock- Wise or counter-clockwise, respectively, as seen in Fig. l. The loom includes in its construction a cross beam 21 the purpose of which will appear hereinafter. During the time that a new tube 1 frame is moving to transfer position the pullover shaft should be free to turn under the action of cam 20, but during the interval Vin which a tube 'shaft II should be held stationary. The parts thus .far described are yof usual construction and to a shaft rotating in I may be made and operated in the ordinary time to permit manual or other turning f shaft |I when the shield is in neutral position.

In the preferred form of invention we secure a stand to the under side of the cross beam 21 and provide the same with spaced left and right end bearings 3| and 32, respectively, in which are loosely tted sliding studs 33 and 34, respectively. 'Each stud has associated therewith a brake arm, the left arm 35 having "a hub 36 which receives the stud 33, and the right arm 31 having a hub 38 to receive the right stud 34. The studs are held in longitudinally adjusted positions in their respective hubs by lock nuts 39 and the studs have their adjacent ends reduced for cooperation withgthe pistons of a hydraulic brake cylinder designated generally at 40.y

Cylinder 40 comprises a main body 4| bolted at 42 to the bracket or stand 30. The body has therein a cylindrical bore 43 which receives at its right and left ends, respectively, pistons 44 and 45 each having a pressure head 46 to bear against the reduced end of the adjacent stud. A tension spring 41 held by clips 48 on the studs as shown in Fig. 2 tends to move Athe hubs 36 and 38 toward each other against' the action of brake cylinder 40. l v

The bottom shaft 2|V has secured thereto a cam formed with a relatively long high dwell 5| and a shorter low dwell 52. A cam lever 53 moves about a pivot 54 xed on the loom frame and has a short arm 55 for cooperation with a master hydraulic cylinder fastened to the loom frame. A spring pressure rod 6| supported and guided as shown in Fig. 1 urges the roll 62 of lever 53 against the face of the camI 50. The master cylinder has an internal bore 65, see Fig. 9, in which is slidable a piston having a projecting stem 61 for engagement with the arm'55. A hydraulic tube 63 connects the bore of cylinder 60 with the bore of the brake cylinder 40.

rIn the preferred form of brake arm mounting shown in Fig. 2 the arms 35 and 31 are formed with substantially semi-'circular shoes 'I0 and 1|, respectively, each lined with a friction material or pad 12,- such as leather, shaped and positioned for engagement with the spullover shaft The lower ends of the shoes are connected to a link 15 by means of eccentric studs 16 and 11, rotatable, respectively, with the arms 35 and 31. Since the eccentric studs are both alike'and as shown in Fig. 5, only one of them will be de-` scribed in detail. Stud 16 has right and left reduced trunnions andrl, respectively, between which extends the larger eccentric 82 passing through a bore 83 in the bottom of shoe 19. 'The gudgeon 80 extends through the link 15 and has secured to the right end thereof a handle 85. 1-

The left gudgeon 8| extends through a link 86 similar to link15 and held against shoe 10 :by a nut 81. The link 86 and nuts 81 normally hold the handles and their eccentrics in such position as to draw the lower ends of the shoes `I0 and 1| together, but when the handles are thrown away from each other the eccentrics act to separate the shoes 10 and 1| as shown in dotted lines, Fig. 4, for the purpose of relieving pressure between the pullover shaft and the pressure exerted by nuts the eccentrics in normal loom operation, but are leather pads 12. The 81 is sufficient to retain position during ordinary not too tight to permit turning of the eccentric by handles 85. f

The modiiied form of attachment for the lower ends of the brake arms is shown in Figs. 6 and 7. The stand 30 has secured thereto a depending U-shaped support 90 in the lower end of fwhich is secured the reduced end of a stud 9| held in angularly adjusted position by lock nut 92. The larger end of the stud has loosely journaled thereon combined top and bottom eccentrics 93 and 94, respectively, received by eccentric straps 95 and 96, respectively, of shoes 91 and 98 rcorresponding to shoes 10 and 1|. vThe right end of stud 9| as seen in Fig. '1 is threaded as at 99 to receive the similarly threaded hub |00 of a handle |0|. A web |02 on hub |00 carries a pin |03 fixed With respect to the eccentrlcs, as by being tapped into eccentric 93'. Undery normal` conditions the eccentrics 93 ,and 94 will be clamped between the lower end of support 90 and hub |00 as shown in Fig. 6 to serve as stationary pivots for their respective shoes. When handle |0| is. thrown to the right, Fig. 6, the hub |00 moves along threaded end 99 of stud 9| to relieve pressure on the eccentrics and at the same time shift vthe latter in opposite directions laterally to Aseparate shoes91 and 98 to release shaft It is believed -that the operation of our invention will be apparent from the yforegoing description. Under normal conditions the eccentrics in both the preferred and the modified forms Will be so located as to draw the lower ends of the brake shoes together. Under these conditions high dwell 5| of cam 50 can cause lever 53 to move .the stem. 61 of the master cylinder inwardly to maintain a high degree of iluid pressure within the hydraulic system tending to move the lpistons of the brake cylinder in such a'direction as to force the brake arms against shaft During the time that the pullover shaft is to be locked while a tube frame is detached from the chain C, moved to tuft forming position, and returned to the chain, dwell 5| will push stem 61 to the left, Figs. 1 and 9. Subsequent to the tuft forming operation, the low dwell 52 permits lever 53 to be moved in a direction by its spring plunger 6| such as will permit a reduction ofA fluid pressure Within the hydraulic system and the brake shoes will slacken their grip on the pullover shaft. Thespring 41 may be used to assist in moving the brake shoes away from shaft I i, but it is not necessary under all conditions, inasmuch as a mere reduction'of fluid pressure within the brake cylinder will relieve the braking eifect suiciently to permit the pullover shaft to turn.

The cam 20 is so related to the cam 50 that the start of a working stroke of the arms |3 and `I4 coincidesk with a reduction of the braking force effected by cam 50. The armsl 35 and 31 will tend to have a slight angular movement varound shaft when moving relatively to each ,regardless of the position of From the foregoing it will be seen that we have provided a simple form of brake mechanism for the pullover shaft of an Axminster loom including a hydraulic brake cylinder located between brake arms and operative normally to maintain braking force but releasable so that the shaft can be rocked to advance the next tube frame to the transfer station. It will also be seen that the shoes rock about eccentrically mounted pivots which can be moved angularly in a manual operation separate the shoes and relieve their braking effect on the pullover shaft, and this movement of the eccentrics can occur cams 2U and 50. It will further be seen that in the preferred form of the invention each brake shoe has its own eccentric mounting, while in the modified form a double eccentric on a single axis serves as a mounting for the brake shoes. In both instances, however, the connections between the brake shoes includes an eccentric which serves as a pivotal connection between the shoes but which can be rocked manually to effect release of brake pressure on the shaft Il. The combining of the shoe pivots with the releasing of the braking force is a feature of our not necessarily associated with hydraulic means to operate the brake arms.

That part of the foregoing description relating to the Axminster loom construction is not claimed herein, ,this application being directed more particularly to the brake structure.

Having thus described our invention it will be seen that changes and modifications may be made therein bythose skilled in the art without departing from the spirit and scope of the invention, and we do not wish to be limited to the details herein disclosed, but what we claim is:

1. In an Axminster loom having a pullover shaft for'the tube frame transporting chains, a pair of brake shoes disposed around said shaft, a link extending between said shoes, an eccentric connected to said link for each of said shoes, and means connected to said shoes capable of moving the latter into braking relation with respect to the shaft, said eccentrics in normal position causing the means to apply a braking force on said shaft through said shoes, but said eccentrics when shifted from normal position preventing said means from transmitting braking.

force through said shoes to the shaft.

2. In an Axminster loom having a pullover shaft for the tube frame transporting chains, brake shoes disposed around said shaft, a stud in each shoe having a gudgeon and a portion eccentric with respect to said gudgeon, a link connecting said gudgeons, and means connected to'said shoes capable of moving the latter toward said shaft, position causing said means to apply braking force to the shaft through said shoes, and said eccentrics when moved from normal position preventing said means from applying braking force through said shoes to said shaft.

3. In an Axminster loom having a pullover shaft for the tube frame transporting chains, a pair of brake shoes disposed around said shaft,

inventionV said eccentrics when in normal' ing through said link a link extending between said shoes, two eccentrics independently movable with respect to each other, one eccentric connecting one end of the link with one of the shoes and the other eccentric connecting the other end of the link with the other shoe, and means connected to said shoes capable of moving the latter into braking relation with respect to said shaft, said eccentrics in normal position causing the means to apply a-braking force on said shaft through said shoes, and said eccentrics when shifted from normal position acting through said link to prevent said means from transmitting a braking force through said shoes to the shaft.

4. In an Axminster loom having a pullover.

shaft with a tube frame transporting chain, a pair of brake shoes disposed around said shaft, a link extending from one shoe to the other shoe, an eccentric for each shoe operatively connected to said link, and hydraulic means connected to said shoes capable of moving the latter into braking relation with respect to said shaft, said hydraulic means operative are in normal position to apply a braking force to said shaft through said shoes, and said eccentrics when shifted from normal position operating by a force transmitted through said link to prevent said hydraulic means from transmitting a braking force through said shoes to said shaft. l

-5. In an .Axminster loom having a pullover shaft for the tube frame transporting chains, brake shoes disposed around said shaft, a link connected at one end thereof to one of said shoes and extending therefrom to the other shoe, an eccentric connecting the other end of saidlink to said other shoe, and means connected to said shoes on said shaft when the eccentric is in normal position, and said eccentric when shifted from normal position preventing said means from transmitting a braking force through said other end portion of the eccentric to hold the latter in nomal position, and actuating means connected to said shoes capable. of moving the the eccentric is inA normal position, Aand said eccentric when shifted from normal position actto prevent said actuating means from transmitting said lbraking force through said shoes to said shaft.

NORMAN FLETCHER. WALTER Y. ROBB.

when the eccentrics 

